Answer:
(a) 300 W
(b)0.90 J
Explanation:
(a) The electric power for any circuit element is given as
Here I is current passing in the circuit and V is the voltage.
Given I = 12 A and V =25 V.
Substitute the given values, we get
P = 300 W.
Thus, the power defibrillator deliver to the body is 300 W.
(b) To calculate the electric energy use the relation between electric energy, power and time as
Given t = 3 ms.
Substitute the values, we get
E = 0.90 J.
Thus, the energy transferred is 0.90 J.
One of two things is true about this question: EITHER it can't happen
as you've described it, OR you've left out some vital information.
-- IF the first stone was thrown downward with an initial speed and the
second one was dropped from rest 1 second later, then the second one
can never catch up with the first one, and they can never hit the water together.
-- IF the first stone was thrown downward with an initial speed, AND the
second one was released 1 second later, AND they actually do hit the
water together, THEN the second stone must have been given an initial
downward speed greater than 2 m/s, otherwise it could never catch up
with the first one.
Note:
The masses and weights of the stones are irrelevant and not needed.
=======================================================
An afterthought . . . . .
If the first stone was tossed UP at 2 m/s . . . that could be the meaning of the
prominent plus-sign that you wrote next to the 2 . . . then it rises for (2/9.8) second, then begins to fall, and passes the mountain climber's hand on the way down (4/9.8) second after he tossed it, falling at the same 2.0 m/s downward.
From there, it still has 50m to go before it hits the water.
50 = 2 T + 1/2 G T²
4.9 T² + 2 T - 50 = 0
T = 3 seconds
The first stone hits the water 3 seconds after passing the mountain climber's hand on the way down at a downward speed of 2.0 m/s. In that 3 seconds, it gains (3 x 9.8) = 29.4 m/s of additional speed, hitting the water at (29.4 + 2) = 31.4 m/s .
This is all just a guess, assuming that the 2.0 m/s was an UPWARD launch.
Maybe I'll come back later and calculate the second stone.
Is there a list of answers you can choose from?
Answer:
e=mc2 made to relate mass with energy . bcoz energy can neither b created nor b destroyed
Mg = 6.2 x 9.81 = 60.822
This is also normal force.
Coefficient of friction times normal force is the force due to friction:
60.822 x 0.24 = 14.6N
F = MA so F(your force) - F(friction) = 6.2 x 0.5
= 3.1
Your answer is 3.1+ 14.6
I hope this is correct though I might be wrong.